1. Field of the Invention
The invention relates to copper compounds and to a process for depositing a copper-containing layer on a substrate.
2. Review of Related Art
It has been known to modify substrates by coating the surfaces thereof in such a manner that the surface will have certain functional properties. For example, electroconductive layers, e.g., conductor paths, can be applied onto substrates.
From EP-0 472 897 A1 (DE-41 24 686 A1) there has been known a process for depositing copper-containing layers on substrates, which process utilizes copper compounds containing cyclopentadienyl or substituted cyclopentadienyl.
J.A.T. NORMAN, ET AL. (Journal de Physique IV, Col. C2, suppl. Journal de Physique II, Vol. 1, 1991, C2-271) describe the deposition of copper-containing layers by means of hexafluoroacetylacetonato (trimethylvinylsilane) copper (I) (RCuTMVS). The authors describe a decomposition mechanism including a disproportionation according to the following mechanism: EQU 2 R-Cu-TMVS.fwdarw.Cu+R.sub.2 Cu+2 TMVS (1)
This composition mechanism (1) has been confirmed by other authors also for other compounds of the type R-Cu-L', for example by M. J. HAMPDEN-SMITH ET AL. (Advanced Materials, 1991, Vol. 3, page 246f) for compounds wherein L' represents trialkylphosphane, inter alia. The decomposition mechanism (1) has the inherent drawback that the maximum copper yield attainable for the layer is just 50%, i.e. at least half of the amount of the starting compound will be lost.